Fidelity of DNA and RNA polymerases as influenced by metal-dependent incorporation of ribonucleotides in DNA and deoxyribonucleotides in RNA. NMR studies of tRNA including 31P NMR of tRNA vs aminoacylated tRNA and 19F NMR of F-uracil substituted tRNA (in collaboration with Dr. Jack Horowitz, University of Iowa). 31P NMR of EF-Tu nucleotide complexes and identification of X-P, an intermediate observed in 31P NMR during GTP hydrolysis. Comparison of metal dependent reversal pattern of ATP alpha S and ATP beta S for the acetate kinase and acetyl-CoA synthetase reactions which have the same substrates but are a phosphoryl and adenyl transfer reaction respectively.